The invention relates to a method for integrally extracting levamisole hydrochloride by continuous distillation and drum crystallization. The method comprises the following steps of: enabling levamisole hydrochloride aqueous solution as a raw material to enter a rectifying tower by adopting a continuous medium feeding mode, wherein the tower top has the temperature of 99-102 DEG C and the tower reactor has the temperature of 124-127 DEG C; separating the raw material, wherein component on the tower top is water and the component in the tower reactor is levamisole hydrochlorid enrichment solution with the content of more than 85 percent and the yield of more than 89.9 percent; condensing the levamisole hydrochloride enrichment solution and crystallizing in a continuous drum crystallizationdevice at a crystallization temperature controlled between 4 DEG C below zero and 3 DEG C below zero for 0.3-0.5h, extracting the crystal, filtering and drying to obtain a finished levamisole hydrochloride product with the concentration of more than 99 percent and the yield of 98.7 percent.